Attention frustrated Black Friday shoppers who can never grab that hot product: Wal-Mart is hoping to relieve some of that anxiety.

The world’s largest retailer is throwing its doors open at 8 p.m. on Thanksgiving Day, two hours earlier than a year ago. It’s also guaranteeing shoppers that it will have three of the most popular items it sells if they line up inside the store during a one-hour event that day.

Those who are lined up inside the store between 10 p.m and 11 p.m. on Thanksgiving will be able to purchase the following items: an Apple iPad 2 with Wi-Fi for $399 plus a $74 Wal-Mart gift card; an Emerson 32-inch LCD TV for $148, down from the original $228; and an LG Blu-ray Disc player for $38, about half off the original price.

For those who are inside the store during that one-hour window on Thanksgiving and find the product sold out, Wal-Mart will offer a guarantee card for the item. The item must be paid for by midnight and registered online. The product will then be shipped to the store where it was purchased for the customer to pick up before Dec. 25.

“We know it’s frustrating for customers to shop on Black Friday and not get the items they want,” said Duncan MacNaughton, chief merchandising and marketing officer at Wal-Mart’s U.S. division. To satisfy customers’ demands for coveted items, Wal-Mart “bought very deep” on products that matter to its customers, he said.

MacNaughton declined to offer details but he told reporters Wednesday the discounter is offering sharper discounts and broader, deeper assortments for the kickoff and the rest of the season compared to years past. For example, Wal-Mart doubled the number of tablet computers it’s bringing in for the winter holidays.

The stepped-up strategy comes as Wal-Mart, based in Bentonville, is counting on keeping its momentum going at its U.S. business, which started roaring back late last year after struggling during a more than two-year slump. It’s critical for the holiday shopping season, which accounts for as much as 40 percent of a retailer’s annual sales.

Wal-Mart’s strategy raises the competitive stakes for the start of the holiday season. American retailers have increasingly expanded their hours on Black Friday to get ahead of the competition, but now the kickoff is creeping earlier into Thanksgiving Day.

Starting with the 8 p.m. sale on Thanksgiving, Wal-Mart will have two more rounds of sales that will also include a consumer electronics sale two hours later and a sale at 5 a.m. on Friday.